1. Field of Invention
The present invention relates to a vehicle, and more particularly to a twist vehicle incorporated with a safety driving arrangement which is capable of enhancing general stability of the twist vehicle while it is moving.
2. Description of Related Arts
Conventional twist vehicles have provided people, and especially children, an opportunity to entertain and do reasonable amount of exercise at the same time. Thus, they become more and more popular in the marketplace.
Referring to FIG. 1 of the drawings, a conventional twist vehicle 1P usually comprises a vehicle frame 10P, a rear wheel assembly 20P rotatably mounted on a rear portion of the vehicle frame 10P, a triangular twisting member 30P, a pair of driving wheels 32P rotatably and spacedly mounted on two corner portions of the twisting member 30P respectively, a steering member 40P rotatably provided on the vehicle frame 10P for driving and controlling the twist vehicle to move in a particular desirable direction, and a connecting member 50P which has a upper controlling end connected to the steering member 33P, and a lower driving end connected to a front corner portion of the twisting member 30P. Whereby, when twisting motions—subsequent clockwise and anti-clockwise movement are imparted to the steering member such as that imparted by a rider of the twist vehicle 1P, the twisting motions will be transmitted to the twisting member 30P via the connecting member 50P, and as a result, the twisting member 30P rotates accordingly about the connecting member 50P. The driving wheels 32P then drive the twist vehicle 1P to move.
Very often, a supporting wheel is rotatably mounted on the front corner portion of the twisting member 30P for supporting the twisting member 30P while the twist vehicle 1P is moving.
One skilled in the art should appreciate that the major reason which makes the twist vehicle to move hinges upon the geometrical arrangement of the driving wheels 32P. Specifically, the pair of driving wheels 32P must be spacedly apart from each other and that each of the driving wheels 32P must be spacedly apart from the axis of twisting, i.e. the corner portion of the twisting member 30P, or the supporting wheel. These geometrical constraints must be satisfied to ensure the twist vehicle's ‘enablement’.
Due to the above geometrical constraints, the twisting member 30P of the conventional twist vehicle 1P is therefore triangular in shape, wherein the pair of driving wheels 32P is mounted at two rear corners of the twisting member 30P, while the supporting wheel is mounted in front of the driving wheels 32P. As a result, the axis of rotation while the twisting member 30P is being twisted is not coincident with the center of gravity of the triangular twisting member 30P. As a matter of fact, as the axis of rotation is shifted a little bit forward as compared with the center of gravity of the twisting member 30P, the rider may lose balance easily while driving and the whole twist vehicle may flip over. Besides, it is the triangular twisting member 30P that lacks supporting strength (because of its shape) to substantially support the twist vehicle.
Moreover, conventional twist vehicles 1P suffer a pressing disadvantage of being unstable while moving. As stated above, the moving of the twist vehicle 1P is essentially driven by the twisting of the twisting member 30P, caused by the twisting of the steering member 40P. Therefore, the inherent structure and operation principle of conventional twist vehicle 1P induces its own instability.
On the other hand, it is expected that most of the riders of conventional twist vehicles 1P are children whose ability to balance themselves and control the twist vehicle are limited. Thus, when a child is riding the twist vehicle 1P, due to its inherent instability, the whole vehicle may be flipped over, as reasoned above. This is particularly true when the vehicle is turning around. The child involved may be knocked down on the ground in which the vehicle moved on. The consequence of such incident can be disastrous. In view of the above, anyone skilled in the art cannot simply afford to ignore the safety issue of the twist vehicle 1P.